The present invention relates generally to an improved cross-flow membrane system for separating water or other fluids into a permeate stream and a concentrate stream, and more particularly to a flow control manifold for a cross-flow membrane system, which greatly simplifies the structure of the system, renders the same much less expensive and provides for improved operation.
Cross-flow membrane systems have existed in the art for many years. In general, cross-flow membrane filtration systems involve the removal of ionic, organic and suspended impurities from water or other fluids by passing such fluid, under pressure, across a membrane. As referred to herein, a cross-flow membrane system includes a feed water inlet, a concentrate outlet and a pump or other means for pressurizing the feed water and exposing it to one surface of a semipermeable membrane. Typical cross-flow membrane systems include reverse osmosis (RO), microfiltration (MF) and ultrafiltration (UF). Because of the pore size and other characteristics of the membrane, various ionic, organic and other impurities in the feed water or fluid are prevented from passing through the membrane. Thus, that portion of the water or other fluid which is able to pass through the membrane is relatively free of any of such impurities. The portion of the fluid which passes through the membrane is called the permeate. The portion of the fluid, with impurities therein, which is rejected by the membrane is referred to as the concentrate. Following passage of the water or other fluid through the cross-flow module, the respective permeate and concentrate streams are directed for further use or processing. In many cross-flow membrane systems, a portion of the concentrate stream is recycled.
Although the basic plumbing and hydraulic operation of a cross-flow membrane system appears to be quite simple and uncomplicated, a relatively large number of valves, filters, connections, hoses, conductivity probes, flow control orifices, etc., are needed for operation of such a system. Also, the successful long-term operation and economical design of a cross-flow membrane system includes the need to carefully control and regulate fluid flow rates and pressure via valves and orifices. In the past, these elements have been individually positioned within the system, with each element being connected with its operatively associated elements via various hoses, fittings, etc. As a result, such cross-flow membrane systems in the past have been quite cluttered and complicated and relatively expensive to manufacture and maintain.
Accordingly, there is a need in the art for a cross-flow membrane system which is relatively simple in construction, but which still provides all of the elements needed to have a fully operative system.